The present invention relates to a chemically resistant coated fabric laminate which may be used as a top enclosure for a chemical storage tank. The invention also relates to a chemically resistant coated fabric laminate having resistance to permeation by chemicals.
Heretofore, the commonly used chemically resistant coated fabric laminates were typically fabrics coated on either side with nitrile or polyurethane rubber.
Where it was desired that the permeation rate of a chemical being contained by the fabric be low, a barrier film was incorporated into the laminate by applying a film such as a nylon or other similar soluble coating from the solution.
An example of a complex laminate of this type is contained in U.S. Pat. No. 3,951,190 for a heat-resistant fuel cell. This invention relates to a barrier layer, such as nylon or epoxy, to contain the fuel. A fabric ply was attached to either side of the barrier layer through an adhesive. A polyurethane was then applied to the fabric ply. The side of the fabric ply adhered to the adhesive generally had a nitrile rubber coating.
Such prior art teaching the use of barriers applied from solution limits the utility of such chemically resistant coated fabric laminates, since the number and quality of available soluble barrier resins is limited. In this invention, barriers in the form of thin performed films of inert materials are used in the laminate.
The use of the thin performed films of inert materials as a barrier is simplified by using a layer of rubber, having incorporated therein, an adhesive between the film and the impregnated fabric. Prior art has always held that inert films could only be adhered to rubber by the use of a solvent-based adhesive applied to the film. This procedure is not desired in the production of rubberized fabrics due to the nature of the equipment common to the industry.
The use of dry rubber having incorporated therein an adhesive is taught in the prior art to be of utility in bonding rubber to certain woven fabrics for use in tires and rubber hose. Prior art has never shown that such a technique could be used in bonding inert films to rubber, and indeed the potential utility of such laminates has never been recognized.